APS March Meeting 2026, Day 2

Key Takeaways

• NiPS3 monolayer shows 2D XY BKT transition
• Cr spin detector reveals antiferromagnetic influence on spin Seebeck
• Hematite enables GHz–THz antiferromagnetic resonance rectification
• IBM uses electric fields to tune TLS in superconducting qubits
• Airsoft‑driven mechanoluminescence demonstrates controllable light emission

Summary

Day two of the APS March Meeting showcased cutting‑edge research across condensed‑matter physics and quantum technologies. Edoardo Baldini reported a Berezinskii–Kosterlitz–Thouless transition in monolayer NiPS3, confirming 2D XY magnetism via second‑harmonic generation microscopy. Barry Zink demonstrated how a chromium spin detector and an intervening IrMn layer modify spin‑Seebeck signals in YIG, while Romain LeBrun highlighted GHz‑THz antiferromagnetic spintronic phenomena in hematite, NiO and BiFeO3. IBM’s Andrew Dane described electric‑field control of two‑level systems in superconducting qubits and a novel "percussive maintenance" technique, and a mechanoluminescence experiment used an airsoft pellet gun to trigger light emission.

Pulse Analysis

The observation of a Berezinskii–Kosterlitz–Thouless (BKT) transition in a single‑layer van der Waals magnet marks a milestone for two‑dimensional quantum materials. By employing second‑harmonic generation microscopy, researchers tracked magnetic ordering in NiPS3 down to the monolayer limit, confirming it behaves as a 2D XY system. This insight deepens our understanding of low‑dimensional phase transitions and opens avenues for engineering ultra‑thin magnetic components in spin‑based logic and memory devices.

Spintronic research at the meeting emphasized the role of antiferromagnets in high‑frequency applications. Barry Zink’s work with a chromium spin detector revealed how antiferromagnetic Cr and an IrMn interlayer modulate spin‑Seebeck currents in yttrium iron garnet, offering a tunable platform for magnonic signal processing. Complementary studies on hematite, NiO and BiFeO3 demonstrated GHz‑THz antiferromagnetic resonance, nonlinear dynamics, and optically driven phonon‑mediated spin currents that generate coherent terahertz pulses, positioning antiferromagnets as promising sources for next‑generation wireless and imaging technologies.

On the quantum computing front, IBM’s investigation into two‑level systems (TLS) highlighted their pervasive impact on superconducting qubit coherence. By applying localized electric fields via suspended electrodes, the team could shift TLS energies, while a surprising "percussive maintenance" method—mechanically jolting the cryostat—altered the TLS distribution without a clear mechanism. These strategies aim to mitigate decoherence, a critical hurdle for scalable quantum processors. Meanwhile, a playful yet informative mechanoluminescence experiment used an airsoft pellet gun to induce controlled light emission, underscoring the creative experimental approaches emerging in modern condensed‑matter physics.